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Question 1

Jervell and Lange Nielsen syndrome

Answer 1

AR congenital long QT syndrome caused by molecular defects in potassium channels

Question 2

Treatment for Jervell and Lange Nielsen

Answer 2

Refraining from vigorous exercise, avoiding rx that can lengthen QT, maintaining normal levels of calcium potassium and magnesium, and pharmacotherapy. Beta blockers are the medication class of choice to blunt exertion heart rate and shorten the QT interval. Symptomatic patients or those with hx of syncope require beta blockers PLUS long term pacemaker placement.

Question 3

What condition should be suspected in a cyanotic infant with LAD and small/absent R waves?

Answer 3

Tricuspid valve atresia. The lack of communication between right heart chambers causes hypo plastic right ventricle and diminished RV forces on ECG. The lack of blood flow to the right ventricle and pulmonary outflow tract consequently results in underdevelopment of the pulmonary valve and/or artery. Pulmonary under circulation is the reason for decreased pulm markings on chest X-ray.

Question 4

In a patient with tricuspid valve atresia, what is necessary of survival?

Answer 4

Atrial and ventricular septal defects, allowing for mixing of oxygenated and deoxygenated blood to provide some oxygenated blood for the systemic circulation. The ASD permits increased blood flow to RA and subsequent enlargement, resulting in tall peaked P waves.